Front load pressure jacket system with syringe holder

ABSTRACT

The pressure jacket systems of the invention are used to permit the front loading and removal of a syringe from an injector and include a first jacket segment and a second jacket segment surrounding the exterior surface of the syringe, interior surfaces comformable to the exterior surface of the syringe, a mechanism which allows movement of the first jacket segment in relation to the second jacket segment to permit insertion and removal of the syringe from the pressure jacket, and a mechanism for securing the first and second jacket segments in a fixed relationship upon insertion of the syringe.

This application is a division of application Ser. No. 08/519,201 filedAug. 25,1995 which application is now U.S. Pat. No. 5,779,675 abandoned.

TECHNICAL FIELD OF THE INVENTION

This invention relates to pressure jacket systems for securing a syringein an injector head. More specifically, the invention relates topressure jacket systems which allow front loading and removal of asyringe, and which hold the syringe securely to an injector head duringinjection procedures.

BACKGROUND OF INVENTION

In the medical field, patients often are injected with fluids inprocedures such as angiography. In such procedures, which requirecontrolled injection of a large volume of fluid into a patient, a needleis used as a conduit for the fluid which is connected to the syringe bya connector tube. The syringe is mounted on a motorized injector havingan injector head.

For long term compatibility with injectable fluids, syringes may be madeof polypropylene with a certain minimum wall thickness. The thickness iscritical as typical pressures of up to 1200 p.s.i. are used to injectthe fluids into a patient. For safety and sanitary reasons, differentdisposable syringes are used-for different fluids and differentpatients.

Pressure jackets are known in the art for enclosing and retainingsyringes while in use. A pressure jacket serves to limit radialexpansion of a syringe which may lead to bursting or to leaks of thepressurized fluid around the seals of the syringe plunger. Anotherfunction of a pressure jacket is to prevent forward motion of thesyringe. For example, typically a force of 2000 pounds is required torestrain the forward motion of a 200 ml syringe with a cross-section of1.7 in ² at 1200 p.s.i.

Certain present pressure jackets are one piece designs, where thesyringe is inserted into the jacket from the rear end of the jacket. Anexample of such a pressure jacket is found in U.S. Pat. No. 4,677,980,assigned to the common assignee of this application. The neck of thesyringe protrudes from the front end of the pressure jacket forconnection of fluid lines which lead to the patient. Because thediameter of the syringe neck is much smaller than that of the syringebarrel, it can withstand both radial and forward force.

However such an arrangement causes a problem when the syringe is removedfrom the pressure jacket. The neck of the syringe must pass through thepresent pressure jacket configurations. This requires the patient fluidpath to be disconnected which presents a potential biohazard and mayresult in spilling fluids onto the pressure jacket. Additionally, fluidspilled during loading and purging air from the syringe may get insidethe pressure jacket and require cleaning.

Thus, a pressure jacket system is needed which permits a syringe to befront loaded onto an injector head and removed from the injector headwithout disconnecting the patient fluid path. Further, a pressure jacketsystem is needed which reduces the materials required for themanufacture of the syringe.

SUMMARY OF INVENTION

The present invention relates to front loadable pressure jacket systemsfor use with injectors having an injector head with a housing and afront opening. A syringe is connected to the injector front opening toallow the flow of fluids through the syringe. A pressure jacket holdsthe syringe to the injector head. A piston extendible through theinjector front opening imparts motive force to a plunger in the syringeto cause fluid flow.

One embodiment of the present invention is a pressure jacket havingfirst and second jacket halves each having interior surfaces conformableto the exterior surface of the syringe. A hinge pin extends from thefront face of the injector head. The first and second jacket halves arerotatably mounted on the hinge pin. The halves may be placed in an openposition allowing insertion and removal of the syringe or a closedposition so that the jacket surrounds the syringe.

A second embodiment of the present invention includes a pressure jacketwith first and second jacket halves, where each jacket half has a frontor distal end aid a rear or proximal end. A hinge for rotationalconnection to the injector's front face allows the first and secondjacket halves to be placed in an open position, allowing insertion andremoval of the syringe, and a closed position such that the jacketsubstantially surrounds the syringe. A locking ring is disposed aroundthe first and second jacket halves. The locking ring is placed in aposition over the front ends of the first and second jacket halves whenin the closed position and the ring is placed in a position near theproximal ends of the jacket halves when in the open position.

A third embodiment of the present invention includes a pressure jacketwhich has a hollow cylinder portion with an open distal end and a rearend coupled to the injector head. The cylinder has at least one lockingfinger having front and rear ends, and a pivot axis disposed near therear end. The pivot axis is connected to the open distal end of thecylinder. The locking finger is pivotable to a closed position such thatthe front end of the finger acts to hold the syringe within thecylinder. The finger is pivotable to an open position to allow theinsertion or removal of the syringe.

A fourth embodiment of the present invention includes a pressure jackethaving a jacket cylinder with an open front end and a rear end coupledto the injector head. A first tie rod has a rear end attached to theinjector head and a front end which is attached to a first front plate.The first front plate is pivotable between a closed position for holdingthe syringe within the jacket cylinder and an open position for allowingthe insertion or removal of the syringe. A second tie rod likewise has arear end attached to the injector head and a front end attached to asecond front plate. The second front plate is pivotable between a closedposition for holding the syringe within the jacket cylinder, and an openposition for allowing the insertion or removal of the syringe.

A fifth embodiment of the present invention includes a pressure jacketwith a jacket cylinder having an open front end and a rear end coupledto the injector head. A first pivot is coupled to the injector head anda first tie rod is attached to the first pivot. A second pivot iscoupled to the injector head and a second tie rod is attached to thesecond pivot. A front retaining plate joining the front ends of the tierods allows the retaining plate to be pivotable between a closedposition for holding the syringe within the jacket cylinder and an openposition to allow the insertion or removal of the syringe from thejacket cylinder.

A sixth embodiment of the present invention includes a pressure jacketwhich has a jacket cylinder formed around a longitudinal axis and havingan open front end and a rear end. The jacket cylinder is transverselypivoted to the front face of the housing to allow the cylinder jacket tobe pivoted between a closed position and an open position. An arm havinga rear end affixed to the injector head is attached to a retainingmember. The retaining member retains the syringe in the jacket cylinderwhen the jacket cylinder is in a closed position. The jacket permits theloading or removal of the syringe when the jacket cylinder is in an openposition.

A seventh embodiment of the present invention includes a pressure jacketwhich has a slidable canopy retractable within the injector head. An armhaving a rear end is coupled to the injector head. The front end of thearm is coupled to a retaining member and retains the syringe. The canopyslides to a closed position to retain the syringe and slides to an openposition to allow the insertion or removal of the syringe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an injector head and front loading syringethat may be used with the embodiments of the present invention;

FIG. 2 is a perspective view of a first embodiment of the invention inan open position;

FIG. 3 is a front elevational view of the first embodiment of theinvention in an open position;

FIG. 4 is a perspective view of the first embodiment of the presentinvention in a closed position;

FIG. 5 is a front elevational view of the first embodiment of thepresent invention in a closed position;

FIG. 6 is a perspective view of a second embodiment of the presentinvention in an open position;

FIG. 7 is a perspective view of the second embodiment of the presentinvention in a closed position;

FIG. 8 is an exploded view of a third embodiment of the presentinvention;

FIG. 9A is an alternate configuration of the locking fingers of thethird embodiment of the present invention in an open position;

FIG. 9B is an alternate configuration of the locking fingers of FIG. 9Ain a closed position;

FIG. 10 is a front elevational view of a third embodiment of the presentinvention in an open position;

FIG. 11 is a front elevational view of the third embodiment of thepresent invention in a closed position;

FIG. 12 is a perspective view of a fourth embodiment of the presentinvention in an open position;

FIG. 13 is a perspective view of the fourth embodiment of the presentinvention in a closed position;

FIG. 14 is a perspective view of a fifth embodiment of the presentinvention in an open position;

FIG. 15 is a perspective view of the fifth embodiment of the presentinvention in a closed position;

FIG. 16 is a perspective view of a sixth embodiment of the presentinvention in an open position;

FIG. 17A is a perspective view of the sixth embodiment of the presentinvention in a closed position;

FIG. 17B is an isolated view of an alternative to the sixth embodimentof the present invention;

FIG. 18 is a perspective view of a seventh embodiment of the presentinvention in a partially open position; and

FIG. 19 is a front elevational view of the seventh embodiment of thepresent invention in a closed position.

DETAILED DESCRIPTION

FIG. 1 shows an injector head indicated generally at 20 and a syringe 22which may be used in connection with various embodiments of the presentinvention. The injector head 20 includes a housing 21 and a front face23. The injector head 20 is used to actuate syringe 22 which is mountedon the injector head 20. The syringe 22 includes a tubular body 24 and aplunger 26 slidably positioned therein. In operation, the rear of thesyringe 22 is fixed in or against an opening 30 on the injector frontface 23. Syringe 22 may be affixed to opening 30 by any suitable means,such as mounting flanges (not shown), as described in U.S. Pat. No.5,383,858, assigned to the common assignee of this application and whichis fully incorporated herein by reference. Any of the pressure jacketsystems which are described below may be used to retain syringe 22 whensyringe 22 is affixed to the injector front face 23. The fluid withinsyringe 22 is pushed forward by a drive means, such as motorized piston32, extendable and retractable through opening 30, which engages therear surface 29 of plunger 26 to push plunger 26 forward in the syringe.

FIGS. 2-3 show views of a first embodiment of the present invention inan open position and FIGS. 4-5 show views of the first embodiment in aclosed position. Specifically, as shown in detail in FIG. 2, a fluidinjector 40 includes a pressure jacket 42 which is of an axially splitor "clam shell" type. The pressure jacket 42 is mounted to the frontface 23 of the injector head 20. When syringe 46 is installed intopressure jacket 42, as more fully described below, motorized piston 32when driven forward, engages a syringe plunger (not shown) and pushesthe plunger forward in the body of a syringe 46 to force fluid out ofthe syringe tip 48. Syringe 46, preferably manufactured of a clearplastic, includes a body 50, a neck 52 connected to the body 50 and aluer connector 54 connected to the neck 52. A connector tube (not shown)may be connected to luer connector 54 which delivers fluid to thepatient.

As shown in FIGS. 2-3, pressure jacket 42 which includes a first jackethalf 56 and a second jacket half 58, is preferably manufactured from aclear plastic so that the position of the plunger within installedsyringe 46 may be observed. The first jacket half 56 and the secondjacket half 58 have interior surfaces, 64 and 66, respectively, whichconform to the exterior surface of the body 50 of the syringe 46. Thefirst and second jacket halves 56 and 58 are joined by a pivot hinge 60which allows the first jacket half 56 and the second jacket half 58 tobe swung to an open position, as shown in FIGS. 2 and 3. Pivot hinge 60has one end thereof affixed to the forward wall of injector head 20 at apoint below injector head opening 30, although in other embodiments thepivot hinge 60 may otherwise be radially displaced from opening 30. Forexample, if it is desired that jacket halves 56 and 58 open to the sideinstead of from the top, the pivot hinge 60 would be positioned to oneside of opening 30. As shown in FIG. 2, the pivot hinge 60 is preferablyparallel to axis A of the injector piston movement. With the pressurejacket 42 in the open position, syringe 46 may be inserted between thefirst jacket half 56 and the second jacket half 58. The two jackethalves 56 and 58 are then closed and locked by means of a latch 62, asshown in FIGS. 4 and 5, which in the illustrated embodiment is attachedto first jacket half 56. Alternatively, one of the first or secondjacket halves 56 or 58 may be fixed to the forward wall 23 of injectorhead 20 and the other jacket half may be pivotly mounted to the forwardwall 23 of injector head 20.

As shown in FIGS. 2-5, the first embodiment of the present inventionallows front loading and removal of syringe 46 and any tubes attachedthereto while minimizing fluid spills. Further, as syringe 46 isretained within pressure jacket 42, the amount of material required tomanufacture syringe 42 is reduced because the pressure jacket 42,instead of the syringe walls, bears the majority of the pressure forceexerted during a fluid injection procedure.

A second embodiment of the present invention is shown in FIGS. 6 and 7.FIG. 6 shows a fluid injector 70 having a pressure jacket system 72 inan open position which permits the loading and removal of a syringe 76.Pressure jacket 72, a generally "alligator jaw" type, is hingedlyaffixed to an injector head 20 to which syringe 76 may be releasablyinstalled. Specifically, as shown in FIG. 7, syringe 76 is held by acombination of a first or top jacket half 78 and a second or bottomjacket half 80, together forming pressure jacket 72, and a locking ring82. Both top jacket half 78 and bottom jacket half 80 are preferablymade of clear plastic and have a semi-cylindrical shape. Interiorsemi-cylindrical surfaces 84 and 86 of top and bottom jacket halves 78and 80, respectively, conform to the exterior surface of the body of thesyringe 76. Jacket halves 78 and 80 have respective rear ends 88 and 90located near the injector front face 23 and front ends 92 and 94 whichcoact to form an opening for the syringe neck 97. The front ends 92 and94 have interior surfaces which mate with the exterior conicaltransition region 96 of syringe 76.

When the top jacket half 78 and bottom jacket half 80 are in the closedposition, as shown in FIG. 7, the locking ring 82 is placed about jackethalves 78 and 80. preferably near the front ends 92 and 94 of jackethalves 78 and 80. The top jacket half 78 is rotatable around a firsthinge pin 98 while the bottom jacket half 80 is rotatable around abottom hinge pin 100. In order to open the pressure jacket 72, thelocking ring 82 is moved along the length of the top jacket half 78 andbottom jacket half 80 to the injector front face 23, as shown in FIG. 6.This allows the pressure jacket 72 to be opened by moving the top jackethalf 78 about the first hinge pin 98 and moving the bottom jacket half80 about the second hinge 100. A link (not shown) between the two jackethalves 78 and 80 may be used to regulate the movement of the two halvesso they move away and toward each other at the same rate. Alternatively,either the top or bottom jacket halves 78 or 80 may be fixed to theinjector front face 23 while the other jacket half is pivotly mounted tothe injector front face 23. While in the open position, the syringe 76may be inserted or removed from the pressure jacket 72. The advantagesrelating to the first embodiment of the present invention, discussedabove, are also realized with this second embodiment.

FIGS. 8-11 show a third embodiment of the present invention. A fluidinjector indicated generally at 110 includes a pressure jacket 112 witha plurality of locking fingers 114 for engaging a syringe 116, shown inan open position in FIG. 10 and a closed position in FIG. 11. Pressurejacket 112 is connected at its rear end 132 to injector head 20 by anysuitable means, such as a threaded connection (not shown). Syringe 116has a cylindrical body 118 having a front end 120 and an open rear end122. The front end 120 of syringe 116 is tapered and connected to a neck124. A disk shaped drip flange 126 is formed around the neck 124.

The pressure jacket 112 includes a hollow cylinder 128 which ispreferably made of clear plastic. A distal end 130 of the cylinder 128is open to allow loading and removal of the syringe 116. The distal end130 of pressure jacket 112 has an outside surface 134 which is slightlysmaller in diameter than that of cylinder 128. The outside surface 134of the distal end 130 is threaded (not shown). A plurality of lockingfingers 114 (in the illustrative embodiment, six are shown) pivot aboutrespective pivot points 136, as shown in FIG. 10. Each locking finger114 has a front end 131, preferably beveled, and a rear end 133. Pivotpoints 136 are located proximate to the rear ends 133 of the lockingfingers 114 and are mounted within channels 138 located on the rim ofdistal end 130. Locking fingers 114 may be kept in position by means offriction and are radially angularly spaced from each other on the rim ofdistal end 130. It is understood that any number of locking fingers maybe used.

As shown in FIGS. 8, 10 and 11, a locking ring 140, generallycylindrical in shape, is threaded on its interior surface and threadedonto the outside surface 134 of the distal end 130 (threads not shown).The front end 142 of the locking ring 140 is a distal annulus extendingradially inwardly to form an open orifice 144 which permits the syringebody 118 to be inserted into pressure jacket 112, but does not permitthe drip flange 126 to be inserted into pressure jacket 112. FIG. 10shows that the front interior surface of the front end 142 is sloped toengage locking fingers 114 when in a closed position, as shown in FIG.11 and more fully described below.

FIGS. 10 and 11 show that the syringe 116 is inserted into locking ring140 and cylinder 128 so that drip flange 126 rests on the front end 142.Locking ring 140 is screwed further onto cylinder 128, and thus, movedtoward the rear end 132 of cylinder 128, as shown in FIG. 11. Lockingfingers 114 are pivoted about there respective pivot points 136 from theopen position of FIG. 10 to the closed position of FIG. 11 by the slopedinterior surface of the locking ring 142 which engages the distal ends133 of the locking fingers 114. Front ends 131 of fingers 114 retainsyringe 116 in place. When locking ring 140 is unscrewed away from thedistal end 130 of the cylinder 128, locking fingers 114 pivot into anopen position. A spring member (not shown) may be used to bias thelocking fingers 114 into the open position. Syringe 116 may then beremoved from or inserted into the pressure jacket 112. The advantagesrelating to the first embodiment, as discussed above, are also realizedby this embodiment.

FIGS. 9A and 9B provide details of an alternative configuration of alocking finger. Specifically, the locking finger 314 of FIGS. 9A and 9Bis an angled locking finger formed by an elongated base member 316 andretaining arm 318, preferably integrally formed therewith. Base member316 is pivotly mounted to cylinder 128 at pivot point 136. The anglebetween base member 316 and arm 318 is similar to the angle of the taperof front end 120 of the syringe 116 to permit maximum retention ofsyringe 116 within pressure jacket 112. As shown in FIG. 9A, syringe 116may be removed from pressure jacket 112 by moving a screw-threadedlocking ring 340 toward pressure jacket rear end 132 on threaded surface134 of cylinder 128. Alternatively, as shown in FIG. 9B, syringe 116 maybe held in place by moving the locking ring 340 away from pressurejacket rear end 132 on threaded surface 134 of cylinder 128. As lockingfingers 314 are angled, retaining arms 318 serve as stops to prevent theaxially outward motion of syringe 116. Thus, locking ring 340 need notinclude a sloped inner surface, as described above.

A fourth embodiment of the present invention is shown in FIGS. 12 and13. FIG. 12 shows a fluid injection system indicated generally at 150having a pressure jacket 152 of a split front plate type, in an openposition, while FIG. 13 shows the pressure jacket 152 in a closedposition. Similar to the third embodiment of the invention, the pressurejacket 152 includes a cylinder portion 164 which may be mounted at itsproximal end 168 to the injector front face 23 by any suitable means,such as screw threads (not shown). A cylindrically-shaped syringe 154including a neck 156 may be inserted into the distal end 166 of pressurejacket cylinder 164. Syringe 154 further includes an alignment flange158 comprising two diametrically opposed radially projecting wings 160and 162 which aid in the alignment of the syringe 154 with respect topressure jacket 152. In a preferred embodiment, flange 158 is disposedin a plane including the axis of the syringe 154.

Syringe 154 is held in place by means of a combination of first andsecond front plates 170 and 172. In a preferred embodiment, first andsecond front plates 170 and 172 are semi-circular in shape, such thateach plate 170 and 172 has one straight margin and one arcuate margin.Plates 170 and 172 each contain semi-circular indentations 174 and 176in their respective straight margins, and these indentations 174 and 176form a neck access 178 for the neck 156 of the syringe 154. The straightmargins of front plates 170 and 172 act as flange slots 180 and 182which conform to the wings 160 and 162 of syringe 154. First front plate170 has an end which is connected to a first tie rod 186, which allowsthe first front plate 170 to be pivoted between an open position of FIG.12 and a closed position of FIG. 13. Similarly, the second front plate172 has an end which is attached to a second tie rod 184, which allowsthe second front plate 172 to be pivoted between the open and closedpositions.

Tie rods 184 and 186 have proximal or rear ends which may simply berotatably mounted to the injector front face 23, or alternativelyattached to gears (not shown) located in injector head 20 for automaticopening and closure. The tie rods 184 and 186 are preferably rigidlyattached to the front plates 170 and 172.

When the pressure jacket 152 is in an open position as shown in FIG. 12,front plates 170 and 172 are pivoted away from the pressure jacket 152by rotating the tie rods 184 and 186. For example, sun and planetarygears (not shown) in the head 20 may provide symmetric rotation of thetie rods 184 and 186. The open position allows the insertion or removalof syringe 154. Once the syringe 154 is inserted within the jacketcylinder 164, the front plates 170 and 172 are pivoted into the closedposition as shown in FIG. 13. In this closed position front plates 170and 172 extend across the front end 166 of jacket cylinder 164. Whenfront plates 170 and 172 are pivoted into the closed position, flangeslots 180 and 182 act with the syringe flange wings 160 and 162 of theflange 158 to force the syringe 154 into proper angular alignment withinpressure jacket 152. In the illustrated embodiment, in proper alignmentthe syringe flange 158 is parallel to the plane formed by the tie rods184 and 186. The flange slots 180 and 182 in conjunction with thesyringe flange 158 also act to prevent the syringe 154 from rotatingduring injector head operation.

FIG. 12 also shows that front plates 170 and 172 include latches 192 and194, respectively, located at respective ends which are remote from ordiametrically opposite from front plate pivot points 188 and 190.Latches 192 and 194 clamp onto the distal ends of tie rods 184 and 186respectively, and are operable to fix the front plates 170 and 172 inthe closed position. Slots 196 and 198 are located near latches 192 and194, respectively, and are conformable to pivot points 188 and 190,respectively, to permit a snug fit when front plates 170 and 172 are ina closed position. Front plates 170 and 172 may also include conicalinterior surfaces (not shown) which conform with the front of thesyringe 154 when front plates are in a closed position.

The advantages of the first embodiment discussed above are realized withthis embodiment. Additionally, the use of flange slots 180 and 182 inconjunction with alignment flange 158 allows automatic alignment of thesyringe 154 to an asymmetrical injector head drive means, such as apiston (not shown).

An alternative to the above embodiment may be realized by making the tierods 184 and 186 integral to the jacket cylinder 164. A secondalternative to the above embodiment may be realized by utilizing asyringe similar to that in FIG. 1 and eliminating the flange slots 180and 182, particularly if there is no need to automatically angularlyalign the syringe 154.

FIGS. 14 and 15 show a fifth embodiment of the present invention. FIG.14 shows a fluid injector indicated generally at 210 having a pressurejacket 212 of a swing front retainer type in an open position. FIG. 15shows the pressure jacket 212 in a closed position. Like the otherembodiments previously discussed, the pressure jacket 212 is mounted atits rear end 220 on the injector front face 23 by any suitable means. Asyringe 214 inserted into the front end 218 of pressure jacket 212, asshown in FIG. 15, includes a neck 226. The syringe 214 is held in placeagainst force exerted by the injector drive means on the syringe plunger(neither shown) by a front retaining plate 222 which has a slot 224 thatallows the neck 226 of the syringe 214 to extend from the cylinder 216through the front retaining plate 222. The slot 224 is significantlysmaller in a direction transverse to the longitudinal axis than thediameter of the syringe 214, so that the remainder of the retainingplate may resist forward-directed force placed on it by the syringe 214during an injection operation. The slot 224 extends from the center ofretaining plate 222 in a direction of the pivot of front plate 222(discussed below) to the margin of plate 222.

In a preferred embodiment, the inside surface of slot 224 is contouredto engage the outside surface of syringe neck 226. For example, if neck226 is cylindrical in shape, the inside surface of slot 224 iscylindrical. If neck 226 is conical in shape, the inside surface of slot224 is angled.

An adapter 228, which is an annular collar for tie rod connections, ismounted or integrally formed on the injector front face 23 and adjoinsthe pressure jacket cylinder 216. The collar 228 has a pair of tie rodpins 230 and 232. Bushings 234 and 236 rotate about tie rod pins 230 and232, forming pivots. Bushings 234 and 236 are connected to and may beintegrally formed with to the rear ends of tie rods 238 and 240. Thefront ends of tie rods 238 and 240 are connected to the front retainingplate 222. It is understood that pins 230 and 232 may be located eitheron the injector front face 23 or on the exterior of jacket cylinder 216.

To open the pressure jacket 212, the tie rods 238 and 240, and frontretaining plate 222 are pivoted about the pins 230 and 232 by bushings234 and 236 which allow the syringe 214 to be inserted into the frontend 218 of the jacket cylinder 216. The front plate 222 and the rods 238and 240 are then pivoted back into place to retain syringe 214. It isunderstood that an alternative to this embodiment may include a frontplate 222 formed by two halves each connected to a rod 238 and 240 suchthat each halve of the front plate 222 is pivoted into place to retainsyringe 214. The advantages relating to the first embodiment, asdiscussed above, are also realized by this embodiment.

FIG. 16 shows a fluid injector indicated generally at 250 having apressure jacket 252 of a "caulking gun" type. Like the embodimentsalready described, the pressure jacket 252, when assembled, permits apiston (not shown) housed within an injector head 20 to apply forwardforce to a plunger (not shown) within a hollow body of a syringe 254,thereby forcing fluid from a front connector end 256 thereof Thepressure jacket 252 has a jacket cylinder 258 which may be made of clearplastic. The jacket cylinder 258 may be rotated about pins 260 and 262(the last shown in phantom) which are rotatably attached to the frontface 264 of the injector head 20. Front face 264 is curved or slantedwhich allows cylinder 258 to pivot about pins 260 and 262. Cylinder 258has an open front end 265 by which the syringe 254 may be loaded orremoved.

Attached to the injector head 20 is the rear end of an elongated arm 266which is disposed in parallel to the longitudinal axis of syringe 254when the latter is loaded into pressure jacket 252 and is ready for aninjection operation. A retaining wall 268 is orthogonally attached tothe front end of arm 266. The retaining wall 268 has an internal surface270 which is generally spherical or conical in shape so as to mate withan external spherical or conical surface of a syringe transition region272 located between a syringe cylindrical body 274 and syringe tip 256.Retaining wall 268 has an upwardly open slot 276 for the insertion ofthe neck 256 of the syringe 254 when the pressure jacket cylinder 258 ismoved to a closed position, as shown in FIG. 17A. The slot 276 is cut inthe same direction as the direction of articulation of the pivotingpressure jacket 252.

As shown in FIG. 16, cylinder 258 of pressure jacket 252 is pivoted toan open position to allow the loading or removal of the syringe 254 intothe open end 265 of the cylinder 258. The cylinder 258 is then pivotedback to rest against the arm 266 and the syringe neck 256 is loweredinto the slot 276 of the retaining wall 268. The advantages discussedabove are also realized by this embodiment.

FIG. 17B shows an alternative embodiment to that shown in FIG. 17A. Aprong 277 attached to cylinder 258 is provided for engaging slot 276 ofretaining wall 268 when the pressure jacket 252 is in the closedposition so as to further secure syringe 254 within pressure jacket 252.

FIGS. 18 and 19 show the final embodiment of the present invention whichis a fluid injector 280 having a pressure jacket 282 of a "slideablecanopy" type for receiving and retaining a syringe 284. The pressurejacket 282 has a canopy 286 which has an open front end 288 and an openrear end 290. Canopy 286 is slidably mounted on the injector head 20. Anopening 292 in the front plate 293 of injector head 20 allows the canopy286 to be retracted within the injector head 20. Canopy 286 ispreferably made of clear plastic. Alternatively, canopy 286 maytelescope into or over a fixed tube which extends from injector head 20(not shown).

An arm 294 has a proximal or rear end mounted on the injector head 20.The opposite, distal or front end of the arm 294 is orthogonallyattached to a retaining wall 296 which has a slot 298 to allow placementof the neck 302 of the syringe 284. In operation, the syringe 284 isplaced on the arm 294 such that the neck 302 of syringe 284 is placedwithin the slot 298 of the retaining wall 296. The retaining wall 296has a conical shape to conform to the front of the syringe 284. In orderto hold the syringe 284 in place, the canopy 286 is moved along the arm294 as by means of a channel 304, as shown in FIG. 19, formed in theinterior surface 306 of the canopy 286. This arrangement allows thecanopy 286 to slide on the arm 294 from an open to a closed position orvice versa, allowing the removal or insertion of syringe 284. Theadvantages discussed above are also realized by this embodiment.

The above described embodiments are merely illustrative of theprinciples of this invention. Other arrangements and advantages may bedevised by those skilled in the art without departing from the spiritand scope of the invention. For example, the drip flange and otherfeatures described here may be used with other systems as well.Accordingly, the invention should be deemed not to be limited to theabove detailed description but only by the spirit and scope of theclaims which follow.

We claim:
 1. A fluid injection apparatus for use with a syringe, thefluid injection apparatus comprising:an injector comprising a housingdefining a front opening therein and drive means extendible through thefront opening of the housing for imparting motive force to a plungerdisposed within the syringe; and a pressure jacket assembly associatedwith the housing for substantially enclosing the syringe during aninjection procedure, the pressure jacket assembly comprising at leastfirst and second jacket portions having interior surfaces conformable tosubstantial portions of an exterior surface of the syringe, and at leastone hinge member coupled to the housing of the injector, at least one ofthe at least first and second jacket portions rotatably mounted on theat least one hinge member and articulable between an open position forallowing insertion and removal of the syringe, and a closed positionwherein the pressure jacket portions are adapted to engage substantialportions of the exterior surface of the syringe.
 2. The fluid injectionapparatus of claim 1 wherein the at least first and second jacketportions are formed from substantially clear plastic.
 3. The fluidinjection apparatus of claim 1 wherein the at least first and secondjacket portions substantially define a semi-cylindrical shape.
 4. Thefluid injection apparatus of claim 1 wherein said pressure jacket, whenin the closed position, is disposed around an axis, and the at least onehinge member is substantially aligned with the axis.
 5. The fluidinjection apparatus of claim 1 wherein the at least first and secondjacket portions comprise three or more jacket portions.
 6. A fluidinjection apparatus for use with a syringe, the fluid injectionapparatus comprising:an injector comprising a housing defining a frontopening therein and drive means extendible through the front opening ofthe housing for imparting motive force to a plunger disposed within thesyringe; and a pressure jacket assembly associated with the housing forsubstantially enclosing the syringe during an injection procedure, thepressure jacket assembly comprising at least first and second jacketportions having interior surfaces conformable to substantial portions ofan exterior surface of the syringe, each jacket portion comprising afront end and a rear end, at least one of the at least first and secondjacket portions comprising a hinge member for rotational coupling to thehousing of the injector, and at least one of the at least first andsecond jacket portions being articulable between an open position forallowing insertion and removal of the syringe, and a closed positionwherein the pressure jacket portions are adapted to engage substantialportions of the exterior surface of the syringe.
 7. The fluid injectionapparatus of claim 6 further comprising means for securing the at leastfirst and second jacket portions together.
 8. The fluid injectionapparatus of claim 7 wherein the securing means comprises a locking ringslidably disposed around the at least first and second jacket portions,said locking ring being positioned near the front ends of the at leastfirst and second jacket portions when the jacket portions are in theclosed position, and said locking ring being positioned near the rearends of the at least first and second jacket portions when the jacketportions are in the open position.
 9. The fluid injection apparatus ofclaim 6 wherein the at least first and second jacket portions are formedfrom substantially clear plastic.
 10. The fluid injection apparatus ofclaim 6 wherein the first jacket half is disposed above the secondjacket half.
 11. The fluid injection apparatus of claim 6 furthercomprising a link coupling the at least first and second jacketportions, said link regulating the movement of the at least first andsecond jacket portions such that the jacket portions move away from andtoward each other at approximately the same rate.
 12. A fluid injectionapparatus for use with a syringe, the fluid injection apparatuscomprising:an injector comprising a housing defining a front openingtherein and drive means extendible through the front opening of thehousing for imparting motive force to a plunger disposed within thesyringe; a first jacket portion connected to the housing of saidinjector, said first jacket portion defining an interior surfaceconformable to a like portion of an exterior surface of the syringe; asecond jacket portion operably connected to at least one of said firstjacket portion and the housing of said injector, said second jacketportion defining an interior surface conformable to another portion ofthe exterior surface of the syringe, said second jacket portion beingarticulable with respect to at least one of said first jacket portionand the housing of said injector between an open position for permittingthe insertion and removal of the syringe, and a closed position in whichsaid first and second jacket portions cooperate for supporting andsubstantially enclosing the syringe on said injector; and a closureconnectively associated with one of said first and second jacketportions for securing one of said jacket portions to the other of saidjacket portions when said first and second jacket portions are in theclosed position.
 13. The fluid injection apparatus of claim 12, furthercomprising at least a third jacket portion for supporting the syringe onsaid injector.
 14. A fluid injection apparatus for use with a syringe,the fluid injection apparatus comprising:an injector comprising ahousing defining a front opening therein and drive means extendiblethrough the front opening of the housing for imparting motive force to aplunger disposed within the syringe; and a pressure jacket assemblycomprisingat least first and second jacket segments operable forengaging a substantial portion of an exterior surface of the syringe, amechanism for allowing the first jacket segment to move in relation tothe second jacket segment to enable insertion of the syringe into saidpressure jacket assembly and removal of the syringe from said pressurejacket assembly, and means for securing the pressure jacket segments ina fixed relationship upon insertion of the syringe to retain the syringetherein.
 15. The fluid injection apparatus of claim 14 wherein the atleast first and second jacket segments comprise three or more jacketsegments.
 16. The fluid injection apparatus of claim 1, furthercomprising a closure for securing the at least first and second jacketportions together.
 17. The fluid injection apparatus of claim 16 whereinthe closure comprises a latch associated with one of the at least firstand second jacket portions.
 18. The fluid injection apparatus of claim16 wherein the closure comprises a ring slidably disposed around the atleast first and second jacket portions.
 19. The fluid injectionapparatus of claim 12 wherein the closure comprises a latch associatedwith one of the first and second jacket portions.
 20. The fluidinjection apparatus of claim 12 wherein the closure comprises a ringslidably disposed around the first and second jacket portions.
 21. Thefluid injection apparatus of claim 12 wherein the second jacket portionis operably connected to the first jacket portion.
 22. The fluidinjection apparatus of claim 21 further comprising a hinge member foroperably connecting the second jacket portion to the first jacketportion.
 23. The fluid injection apparatus of claim 12 wherein thesecond jacket portion is operably connected to the housing.
 24. Thefluid injection apparatus of claim 6 wherein the at least first andsecond jacket portions comprise three or more jacket portions.